In a conventional embedded device having a GUI (Graphical User Interface), service logic defining the behavior of applications and the GUI are typically implemented on the same device so as to be configured as an apparatus capable of independent actions on its own.
Meanwhile, there is another method of constructing a system, such as a server-client system, in which service logic is equipped in a server and a GUI is equipped in a client to collaborate with each other via a network.
By the recent improvement in processing ability of embedded devices and popularization of having a network connection function, the server-client system mentioned above has become applicable to embedded devices, such that a GUI and service logic are implemented on separate devices.
In such a system, communication between the GUI and the service logic, which has been performed within the same device, is replaced by communication between devices. The processing ability of inter-device communication is generally lower than the processing ability of communication within the same device. Further in conventional systems, any event occurring in the service logic is notified to the GUI. The GUI makes a decision whether to use the received events and reflects the result on the GUI. Replacement of communication within the device by inter-device communication results in prolonged time for communication, which follows that the responsive performance of the overall system, for example, the time to be taken from a user's operation of the GUI until the service logic's processing in response to the operation to reflect the processing result on the GUI, is desirably improved by reducing the amount and frequency of inter-device communication. Specifically, unnecessary events are desirably not notified from the service logic to the GUI.
For example, Patent Literature 1 describes that a destination that has requested event notification is registered as a listener, and events are notified to the registered listener, in order to avoid occurrence of unnecessary notification of events. Patent Literature 2 describes that even when an informer program generates events, only an event which has been presented to a notification manager is notified, in order to avoid occurrence of unnecessary notification of events. In so doing, a communication parameter and a dictionary corresponding thereto are used to reduce the amount of communication for specifying one or more events to be presented to the notification manager.